What grain must constitute at least 51% of bourbon production?

Bourbon must have at least 51% corn in its grain bill to be classified as such. This requirement is a defining characteristic of bourbon production. Corn contributes to bourbon's distinctive sweetness and rich flavor profile, setting it apart from other types of whiskey. The use of a high percentage of corn is essential not only for meeting legal standards but also for creating the signature taste that bourbon enthusiasts recognize.

Rye, wheat, and barley can be included in smaller proportions alongside corn to achieve desired flavors, but they do not meet the necessary threshold to define the spirit as bourbon. This focus on corn is what ultimately shapes the identity of bourbon within the world of distilled spirits.